diff --git a/debian/changelog b/debian/changelog
index 25757a4..2eb6179 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -7,6 +7,7 @@ ubuntu-dev-tools (0.123) UNRELEASED; urgency=low
     - Determine distribution from release name (via distro-info).
     - Reformat manpage.
     - Install qemu-user-static instead of qemu-kvm-extras-static.
+    - Correctly substitute release into security suite name.
 
  -- Stefano Rivera <stefanor@debian.org>  Sun, 24 Apr 2011 12:45:31 +0200
 
diff --git a/mk-sbuild b/mk-sbuild
index 6af4801..f149e5e 100755
--- a/mk-sbuild
+++ b/mk-sbuild
@@ -352,7 +352,7 @@ ubuntu)
         COMPONENTS="main restricted universe multiverse"
     fi
     if [ -z "$SOURCES_SECURITY_SUITE" ]; then
-        SOURCES_SECURITY_SUITE="RELEASE-security"
+        SOURCES_SECURITY_SUITE="${RELEASE}-security"
     fi
     if [ -z "$SOURCES_SECURITY_URL" ]; then
         case "$CHROOT_ARCH" in
@@ -389,7 +389,7 @@ debian)
     # Debian only performs security updates
     SKIP_UPDATES=1
     if [ -z "$SOURCES_SECURITY_SUITE" ]; then
-        SOURCES_SECURITY_SUITE="RELEASE/updates"
+        SOURCES_SECURITY_SUITE="$RELEASE/updates"
     fi
     if [ -z "$SOURCES_SECURITY_URL" ]; then
         SOURCES_SECURITY_URL="http://security.debian.org/"